As watchers of Great Spirit Bluff know, we lost two falcons to black flies/buffalo gnats. The young falcons died from blood loss and a blood pathogen carried by black flies. The immune systems of adults can handle the pathogen, but young birds often can't. Although none of us believe that the flies came from within the box, we'll take a sample of gravel for examination as well.
We've had black fly problems here in the past. In 2013 and 2014, young falcons were stampeded from the box in mid-June, when they were roughly 30 days of age. But that we know, we've never had a serious problem this early. Why are black flies swarming the box now? It is a more complicated answer than you might think.
Which black fly is this? There are 30 species of black flies in Minnesota, but not all of them are good candidates for this location. For example, it probably isn't Simulium johannseni (develops primarily in the Crow River) or Simulium meridionale (develops primarily in the Minnesota and Crow rivers), but ruling out those two still leaves 28 possibilities. Although black flies as a whole are grouped into one family (Simuliidae), black fly species have very different life styles. It would be helpful to know which species we are dealing with.
What does its life cycle look like? From Purdue: "The length of time it takes an egg to hatch varies greatly from species to species. Eggs of most species hatch in 4-30 days, but those of certain species may not hatch for a period of several months or longer. The number of larval stages ranges from 4-9, with 7 being the usual number. The duration of larval development ranges from 1-6 months, depending in part on water temperature and food supply. The life cycle stage that passes though winter is the last stage larva attached underwater to rocks, driftwood, and concrete surfaces such as dams and sides of man-made channels." In short, the eggs for the 2017 hatch were most likely laid in 2016. The larvae emerged somewhere between one month ago or six months ago. When I compared average April temperature and precipitation for the area for every year between 2013 and 2017, I found that April 2017 was the warmest, if not by much.
Average Temp (F)
Average Precip (inches)
April 2017
53
4.87
April 2016
50
1.08
April 2015
51
4.16
April 2014
45
7.03
April 2013
43
6.11
The complicated structure of black fly life means that we also need to look at the conditions last fall and winter, which were unusually warm and dry. Did more eggs and larva stay local given the lower river current? Did more larva survive given the unusually mild conditions? Did the slightly warmer April weather lead to an earlier season? Did sun and warm temperatures following days of cold and rain lead to an explosive hatch? John noted that the swarm seemed to blow up and fade very quickly. This video shows 'those dreaded flies': https://youtu.be/Rua_nnLF6TE
Can we control them?
We are looking into it, but we don't have an easy answer yet. We need something that doesn't volatilize since we can't descend to the box every day to spray it. It has to be strong enough to kill flies but not strong enough to harm hatchling and nestling falcons. It can't destroy the integrity of the box or let too much precipitation or wind in through the side. We are contacting the University of Minnesota's insect extension team to pick their brains and have also emailed Dr. Laura Johnson about safe possibilities. John and Susan had an intriguing idea about soaking mesh scrubbies in some known organic repellents and securing them in a safe location inside the nest box, so we may try that as well.
I wish we had more answers for everyone now. We'll do what we can and post more information when we have it.
A sharp-eyed camera operator spotted an unbanded adult peregrine falcon at the Decorah North Nest this morning: https://youtu.be/HyVFISzaqOQ. What a surprise, especially given that there are no cliffs or large rock faces in the immediate area! As we've seen, the North nest is on a flyway of sorts. While almost all of the falcons we watch are on eggs right now, this could be a 'floater' - an unpaired adult falcon with no home territory. If we start seeing or hearing it on a regular basis, we'll need to figure out what it is doing in the area.
Although it isn't common, tree nesting has been documented in peregrine falcons in the United States as recently as 2013. The authors of the short communication Tree-Nesting by Peregrine Falcons in North America: Historical and Additional Records reviewed literature and found 33 North American records of peregrine falcons nesting in trees or snags in Alaska, Kansas, Illinois, Tennessee, Louisiana, Virginia, and British Columbia. However, their field research indicates that tree nesting could be more common than the literature suggests.
Of the 33 tree nests recorded between 1867 and 2007, nine were in tree cavities, nine were in the nests of other raptors (most commonly bald eagles), four were in bole 'platforms' created by a large tree breaking or snapping, and ten were unspecified. Of the nine nests found by the researchers between 1998 and 2013 in California and Washington state, six were in bole platforms, one was in a very large snag, and two were in bald eagle nests.
Peregrine falcons tend to imprint on nest sites, so would they be likely to cross over to trees on their own? The re-establishment of tree nesting peregrines in Europe didn't occur until fledgling peregrine falcons were tree-hacked in a process very similar to Bob's cliff release program. But peregrine falcons have taken over osprey nests with no assistance or direction in New York and New Jersey, and the breeding sites reported by Buchanan, Hamm, Salzer, Diller, and Chinnici are the first documented tree nests used by Peregrine Falcons in Washington and California, the first use of redwoods, Douglas-firs, and grand firs ever recorded, and the first reported snag use by peregrines in North America in over 60 years. As the authors state, Additional records of tree-nesting might be expected if Peregrine Falcon populations continue to increase beyond levels already thought to have exceeded historical abundance (Ratcliffe 1993, Hayes and Buchanan 2002). Given the platform and tree nests in New York, New Jersey, California, and Washington state, it seems that peregrines can change their nesting behavior, although we don't know how likely they are to do so.
One appearance near a bald eagle nest does not make a tree-nesting peregrine population make, but a peregrine in an unexpected place is always exciting to see and we'll keep everybody posted!
A quick end note: as many of you know, Bob identified the 'bird mounds' at Effigy Mounds (and other places) as peregrine falcons in part because they were shaped like peregrine falcons and in part because they were often located near historical peregrine eyries. His research on that can be read here: https://raptorresource.blogspot.com/2015/08/falcon-effigies-of-upper-mississippi.html. When Bob was asked about falcon mounds in places with no cliffs or falcons, such as the Five Hawks effigy mounds once located near Prior Lake, Minnesota, he replied that there had probably been tree-nesting peregrine falcons in the area when the mound builders were active. While we can't know for sure, it is wonderful to think that there may have been tree nesting peregrines in Minnesota, Iowa, and Wisconsin a very long time ago.
What does the Raptor Resource Project do? We are a 501c3 that specializes in the preservation of falcons, eagles, ospreys, hawks, and owls. In addition to bringing you the Decorah Eagles, Great Spirit Bluff Falcons, and other birds of prey, we create, improve, and directly maintain over 50 nests and nest sites, provide training in nest site creation and management, and develop innovations in nest site management and viewing that bring people closer to the natural world. Our mission is to preserve and strengthen raptor populations, expand participation in raptor preservation, and help foster the next generation of preservationists.
As a nonprofit environmental organization, we depend on donors, research, and our other programs for our entire budget. With your tax deductible contribution to the Raptor Resource Project, we can:
Continue updating to high definition digital cameras in Decorah and elsewhere.
Provide one of the world’s largest public wildlife education programs to countless classrooms through our unequaled Ustream channels, interactive chats, facebook page, and blog.
Reboot our kestrel nestbox program. In addition to placing boxes, we plan to monitor, band, and report on kestrel populations as part of the American Kestrel Partnership. Eden Prairie Girl Scout Troop 14286 is providing 12 boxes for installation this year.
Begin a diurnal raptor banding and observation station. Master bander and board member Dave Kester will be in charge of this effort and he is raring to go!
Partner with landowners, private businesses, and government agencies to monitor and band peregrine falcons at over 40 sites. This year we plan to add collection and identification of prey and prey remains to our work.
These things all take money. We have $188,700 budgeted for 2017. Our expenses look like this:
Staff and contracts: $130,000. This includes salaries and compensation for camera installations, maintenance, and climbers for camera work and banding. Since September of 2016, we have had four major installation projects: one at Decorah, one at Decorah North, one at Fort St. Vrain, and one at Xcel Energy's Allen S. King plant in Oak Park Heights, MN. Our falcon surveys will start later this week, weather permitting.
Camera-related expenses: $40,500. This includes our new HD cameras, internet access, computers, video archiving equipment, and related supplies: installation and cable tools and hardware, cable, encoders, software, lumber, solar panels, wireless radios, and all non-staff or contract costs related to purchasing and installing camera systems.
Research-related expenses: $9,000. This includes transmitters, trapping supplies, and data costs, climbing equipment, banding equipment, bands, spotting scopes. permits, and autopsies. We also set some money aside to run a diurnal raptor banding and observation station.
Other/Miscellaneous costs: $9,000. This category includes gasoline, electricity, travel-related costs, equipment fabrication, and propane so we can heat the shed!
Our income is generated primarily by donations from viewers of our various cams, and we sincerely appreciate your generosity and support of the Raptor Resource Project mission. Would you please help us make a difference with your donation? You can donate via Paypal by following this link or mail a check to:
The Raptor Resource Project
PO Box 16
Decorah, IA 52101
Thank you so much for your support and we hope you enjoy watching in 2017!
"When the last individual of a race of living things breathes no more, another Heaven and another Earth must pass before such a one can be again" - William Beebe
Dad Decorah near N2B
What is the Endangered Species Act? Signed into law by President Nixon in 1973, the ESA is the strongest and most important federal law protecting imperiled wildlife and plants. It has prevented hundreds of species from going extinct since it was enacted. Do you enjoy watching Mom and Dad Decorah or any other eagle families? Although they are no longer endangered - protections under the Act are supposed to recover species - the banning of DDT and the passage of the Endangered Species Act was critical to their survival.
Now the Endangered Species Act is under threat from some members of Congress, who see a chance to roll back its influence. “It has never been used for the rehabilitation of species. It’s been used for control of the land,” said House Natural Resources Committee Chairman Rob Bishop. “We’ve missed the entire purpose of the Endangered Species Act. It has been hijacked.”
Bald eagles, peregrine falcons, brown pelicans, California condors, whooping cranes, Puerto Rican parrots, and spotted owls beg to differ with Congressman Bishop's assessment, as do grizzly bears, several species of whales, southern resident orcas, sea otters, gray wolves, and manatees. Unfortunately, recently extinct Carolina parakeets, ivory-billed woodpeckers, passenger pigeons, eskimo curlews, and dusky seaside sparrows are gone forever and thus unavailable for comment.
Peregrine falcon at Xcel Blackdog power plant
I had the privilege of visiting Chicago's Field Museum during a peregrine conference three years ago. Attendees were given a behind-the-scenes tour of the museum, including a look at their vast bird collection - lovingly preserved corpses of birds kept for study and remembrance. It was there that I got my only look at the Carolina parakeet and the ivory-billed woodpecker. Gone forever from life, the two species now exist only as study skins in museums. Had the United States not banned DDT and passed the Endangered Species Act, it is highly likely that peregrine falcons, bald eagles, and many other animals would have joined them, existing only as museum specimens and curiosities on film. However cherished their memories or lovingly preserved their corpses, they too would be gone, dead, extinct, lost. Forever.
Imagine life without them. I can't stand the thought.
Looking for proof of the Act's success? The Center for Biodiversity conducted an exhaustive analysis of bird recovery under the Endangered Species Act and found it has been extraordinarily successful in recovering imperiled birds. Eighty-five percent of bird populations in the continental United States increased or stabilized while protected by the Act, and the average population increase was 624 percent. It was believed that listed bird populations would need 63 years to recover, but several populations (including bald eagles and peregrine falcons) have recovered far more rapidly than expected. As mentioned earlier, peregrine falcons and bald eagles have both been removed from the list.
Dan Berger's notes. All of the Peregrines east of the Mississippi in the surveys he made in the 1950s and early '60s. Not an exaggeration...this was it.
Habitat/land has long been part of the argument against the Endangered Species Act. Those who oppose the act tend to cite the subjection of humans to land use regulation; the restriction of activities like farming, lumbering, construction, and mining, and the lack of compensation to landowners impacted by endangered species. But there are also many untruths in their arguments. Contrary to their arguments:
The Endangered Species Act has recovered species.
Landowners won't lose their homes because an endangered species is on their property.
Conservation groups and biologists do not just want money from the federal government. Folks, I have to tell you - conservation is the wrong field if your goal is money!
It does not kill jobs. Section 7 of the US Endangered Species Act (ESA) directs federal agencies to help conserve listed species. One way it does this is by requiring agencies to consult with the US Fish and Wildlife Service and National Marine Fisheries Service to ensure that proposed federal actions won’t threaten a listed species’ survival. Between 2008 and 2015, 81,461 projects advanced without protections for wildlife, 6,382 advanced requiring only minor modifications for wildlife, 2 advanced requiring protections, and 0 were stopped. This seems to indicate that ESA could work even more effectively than it does now.
I don't understand the argument against preserving habitat. Animals can't live without it and so much is already gone. Why is it considered bad to preserve the 10% of Iowa that isn't under till? Or the Boundary Waters Canoe Area, which covers just 1.9% of Minnesota's total area? Does it really all need to be mined, timbered, and torn up for profit?
I believe in public/private collaborations such as ours and this shining example - how could I not, with what Bob called our 'unique marriage between industry and conservation'? I've seen the power that these relationships can have to secure habitat, change perceptions, and help species. But legislation and enforcement are also necessary, and the reforms being proposed right now are aimed at the destruction of the Act, not its betterment. For the sake of the birds we watch and love, please stand up and say "No" to any attempts to weaken or repeal the Endangered Species Act. We will be following and blogging on this issue and the issue of public land transfer.
Things you can do:
Sign a petition that the American Bird Conservancy will take to Congress. We signed and it endorsed it organizationally, the first time we have done so: http://bit.ly/2k9o2YL
You are welcome to take anything from this blog and re-use it in a letter, email, or editorial. Keep your tone respectful and remember that conservation is not and should not be a partisan issue. But please comment! Bob always believed that we can make a difference. Let's prove him right.
Public land is understandably a far hotter issue in the western United States, where the federal government owns vast tracts of land. But even there, groups like Sportsmen's Access, Backcountry Hunters and Anglers, and the Theodore Roosevelt Conservation Partnership are fighting for public land. I get upset email on our support for hunting and fishing, but I encourage people to take a look at what these groups and others like them are doing to support public lands. They are also an important reminder that conservation isn't, in the words of the Theodore Roosevelt Partnership, red or blue.
It has also been pointed out to me that bald eagles and peregrine falcons live pretty comfortably with humans. But not all species can live as comfortably with humans as bald eagles and peregrine falcons do. Do species that can't matter less than those that can?
And finally, the struggle to preserve wildlife and wildland is, in my opinion, an absolute necessity for our own survival. If they don't make it, we won't either. We aren't an exception to the requirements of clean air, clean water, and habitat, and humans and animals are in this glorious, lovely mess called life together.
We have a day for giving thanks. We have two for getting deals. Now, we have #GivingTuesday, Tuesday, December 1st, a global day dedicated to giving back! If you like the work we do, please consider making a donation. You can donate online via paypal or mail a check to the Raptor Resource Project, PO Box 16, Decorah, IA 52101.
We are celebrating #GivingTuesday with some very special guests on our Decorah Eagles Ustream channel at http://www.ustream.tv/decoraheagles. We'll be starting chat at 8:00am Central Time and running through 8:00pm. Our planned schedule (weather permitting) will be:
10:30 Intro - John Howe
11:00 PE Project Update - Neil & Laura
12:00 Trapping and Monitoring - Dave Kester
3:00 Cameras and Projects Update
We will take questions from chat, although you are also welcome to email questions to amy@raptorresource.org. I can't guarantee we will get to all of them, but please feel welcome to send them!
What does the Raptor Resource Project do? We are a 501c3 that specializes in the preservation of falcons, eagles, ospreys, hawks, and owls. In addition to bringing you the Decorah Eagles, Great Spirit Bluff Falcons, and other birds of prey, we create, improve, and directly maintain over 50 nests and nest sites, provide training in nest site creation and management, and develop innovations in nest site management and viewing that bring people closer to the natural world. Our mission is to preserve and strengthen raptor populations, expand participation in raptor preservation, and help foster the next generation of preservationists.
As a nonprofit environmental organization, we depend on donors, research, and our other programs for our entire budget. With your tax deductible contribution to the Raptor Resource Project, we can:
Continue updating to high definition digital cameras in Decorah and elsewhere.
Help develop and realize a dream of Bob's: establishing a Philippine Eagle cam to save a beautiful bird of prey who's very existence is threatened. We are working in cooperation with the Cornell Lab of Ornithology and the Philippine Eagle Foundation. Neil and Kike will be traveling to the Philippines to scout locations with staff from both organizations in February of 2016.
Provide one of the world’s largest public wildlife education programs to countless classrooms through our unequaled Ustream channels, interactive chats, facebook page, and blog.
Partner with landowners, private businesses, and government agencies to monitor and band peregrine falcons at over 40 sites.
Continue our collaborative raptor nest-box, trapping, and monitoring programs.
These things all take money. As of 2015, our annual expenses were hovering around $99,000 per year:
Staff/Compensation costs were around $55,000. We incurred extra expenses for our N2B build and two camera installs: one at N2B and one at Decorah North Nest. These were intensive projects that required a lot of help. The N2B camera installation alone took five full days of work from dawn past dusk.
Equipment – computers, camera upgrades and maintenance, tools, encoders, software, transmitters, and so on – cost around $27,400.
Other/Miscellaneous costs around $9,000 annually. This category includes gasoline, electricity, travel-related costs, equipment fabrication, and propane so we can heat the shed!
Our income is generated entirely by donations from viewers of our various cams, and we sincerely appreciate your generosity and support of the Raptor Resource Project mission. Would you please help us make a difference with your donation?
Thank you so much for your support and we hope you enjoy watching in 2016!
By now most of you are aware that all four young falcons jumped from the nest box at Great Spirit Bluff on June 17th. They were approximately 10 days away from fledging. Searchers were only able to find one of four falcons. Bob evaluated Jonathon, a male, and decided to augment/foster Jonathon into another nest box rather than risk having him jump out again. He chose Red Wing Grain as the new site, since the two young falcons there are about the same age as Jonathon. We fostered Jonathon on the morning of June 19th and he seems to have adapted quite well to his new surroundings.
We chose not to continue the search after the first night. Like many young animals, the falcons either hide or try to scurry under cover when they hear threats approaching. We didn't want to drive them so deep in into the undergrowth that Michelle and Travis couldn't reach them. Since then, we have heard the young falcons calling from the area below the nest box, and we have witnessed Michelle and Travis carrying what appears to be prey down below. We hope to see the young falcons at the nest box or on the ledge again, but only time will tell.
We have received numerous questions regarding the nest box at Great Spirit Bluff. Is it a safe box? It is. In the Midwest alone, over 1,000 falcons have been produced at nest boxes that use this design, which provides shelter from the weather and perches for sitting. Netting under the boxes is out of the question, since the falcons would snag their talons, and holes or venting in the side of the boxes to let in wind would also let in rain and snow.
Absent external stimuli, Bob has never seen young falcons jump from a nest box or cliff as they did at Great Spirit Bluff. He believes that insects caused the young falcons to stampede from the box. Just a few weeks ago, 17 of 20 adult whooping cranes in central Wisconsin deserted their eggs due to black flies, as reported in the Wausau Daily Herald. http://www.wausaudailyherald.com/article/20130525/WDH01/305250345/Black-flies-endanger-whooping-crane-nests
Please refer to this blog post for more information about insects, intervention, and fosterage: http://raptorresource.blogspot.com/2013/06/great-spirit-bluff-falcons-intervention.html
Although we knew the gnats and black flies were bad, we were unable to intervene earlier, since that would most likely have caused the young falcons to jump before they had developed their flight feathers. In short, the risk of injury or death was higher if we went to the box than if we did not. This was an unusual and unfortunate situation. We haven't seen it before and we hope never to see it again.
To view the Red Wing Falcons, click on this link, and then choose Red Wing Grain Falcons from the left side and click on that link: http://www.farmyou.com/falcon_cams/index.html. This cam may not always be available, since it has limited bandwidth.
A big thank you to the Howe family for responding so quickly, climber Dan for last minute assistance, and the staff of Red Wing Grain for letting us foster a falcon into their box on very short notice. Bob made a difficult decision in a stressful situation, but he made it in the best interests of Jonathan, who is thriving in his new home.
Michelle and Travis hatched two young falcons on 5/13/12, and the questions are already flying! I'll try to answer a few of the most common here.
1. Why are they nesting in gravel? I wish the hatchlings had grass or something softer!
Historically, peregrine falcons nested in two places: on cliffs and in trees. To quote: "Although the peregrine falcon is
currently considered a cliff-nester, records indicate that it once nested in
tree cavities (Goss 1878, Ridgway 1889, Ganier 1932, Bellrose 1938,
Spofford 1942, 1943, 1945, 1947, Peterson 1948). The peregrine still uses
cavities in broken-off trunks in Europe (Hickey 1942), but the hole-nesting
population of America apparently disappeared with the felling of the great trees
on which they depended (Hickey and Anderson 1969)."
Either way, peregrines did not build nests out of branches, twigs, or grasses. Cliff nesting birds use ledges or potholes. These commonly have some kind of substrate: sand, pebbles, dirt, and so on. The male and female dig and wiggle out a scrape, or shallow cavity, into which the female lays her eggs. The substrate provides drainage, cups the eggs, and helps keep them from breaking on the edges of the underlying rock. We use 80 pounds of pea gravel in our nest boxes to simulate a substrate and protect the eggs.
2. How long can the babies go without eating?
The hatchlings consume the egg yolk shortly before hatching, which gives them enough nutrition for 24 to 48 hours. However, they don't usually have to go very long. Their first feeding was at 11:49am CST this morning.
3. What do falcons eat? Falcons eat other birds. We've found the remains of pigeons, woodpeckers, coots, finches, blackbirds, ducks, cuckoos, and many other birds stashed in and around nests. In general, the adults catch a bird by diving or stooping on it. If the impact doesn't kill it, the adults use their tomial tooth - a notch in their beaks - to bite through their prey's cervical vertebrae. They pluck their prey prior to eating: "feather falls" have helped me locate Peregrine falcons at the Mayo Clinic and the Dairyland Alma power plant.
Adult peregrine falcons eat about 2 1/2 ounces (70 grams) of food per day. Using a rough back-of-the-envelope calculation, males average 587 grams of weight and females average 1205. So males eat roughly 11% of their body weight each day. I'm guessing - and this is a guess - that females do the same, so Michelle probably eats a little more than Travis does. It has been speculated that gender-based size differences allow male and female birds of prey to eat from a slightly different prey bases, widening the available food supply.
So based on this calculation, I'd need to eat about 16.5 pounds of food every day to keep up with Michelle.
4. How fast will the babies grow?
Peregrine falcons double their birth weight in 6 days, and are 10 times hatch weight in three weeks.
Like the eaglets, they start with a fluffy white coat of baby down. We'll start to see brown juvenile feathers emerging at about 20 days of age. By 40 days, the young birds will be sleek brown juvenile falcons.
Over the next few weeks, we'll see a lot of eating, sleeping, and pooping. Poop is a great way to locate the nests and perches of many kinds or birds. See bird poop? Look around for the bird!
5. Will Cain and Abel Syndrome be a problem here?I don't want to say 'No', but I haven't seen it at any of the other Peregrine falcon nests we watch. There is an ample food supply and Michelle and Travis are very good at caring for their young.
6. Mom and Dad are talking to the babies!
Yes, they are! We've already heard Michelle echupping encouragingly to her young immediately before their first feeding. We'll also hear the young food begging (which one website describes as 'screea screea screea'), and kakking: an alarm, defense, and 'annoyance' call. Peregrine falcons are very vocal. I've had unhappy babies set my ears to ringing more than once. 7. Does the nest smell bad?
It depends! Some falcons are great housekeepers, while others (I'm looking at you, Hibbard plant falcons) let prey remains pile up in the nest. If the nest is messy, the young birds smell interesting to human banders - not bad, but not pleasant: a complex, spicy smell.
Things that helped me learn and write about Peregrine falcons:
Bob Anderson. He knows more about Peregrine falcons than anyone I know. I should see if he'd be willing to echup on video: it is really amazing. Any mistakes in this blog are mine, not his!
While we wait for eggs to hatch in Decorah, Valmont, and Fort St. Vrain, I thought I would talk a little bit about Peregrine falcons. Prior to the Decorah Bald eagle cam, Peregrine falcon recovery was what we were known for, to the extent we were known at all.
In Flight
The Peregrine is the fastest animal in the world, diving or stooping at speeds that can reach over 200 miles per hour. Almost everything about it is built for speed, from the baffles in its nose to the jagged edges of its slim, stiff feathers and long, pointed wings.
The falcon catches other birds in flight by diving on them from above. As she begins her stoop, she rolls, cups her wings around her body, and tucks in her feet. This change in shape streamlines her profile, yielding an aerodynamic raindrop that can cut through the air at high speeds.
As she plummets her nictitating membrane, a transparent 'third eyelid', protects her eyes from dust and debris in the air and a secretory gland helps keep her corneas from drying up. A special cone or baffle in her nose regulates the amount of air entering her nasal cavity, allowing her to breathe and protecting her from damage. A curved flight path keeps her prey in view and reduces her aerodynamic drag. Before she strikes her prey, she'll experience G-Forces estimated at between 25-27 Gs.
The Peregrine meets her prey feet-first. She slows first, unfurling her wings and tail, and dropping her feet. After striking and stunning or killing it outright, she'll loop around in mid-air to retrieve it and take it to a safe place for plucking and eating.
Falcon Belinda at Xcel Energy's Allen S. King plant aims at a reporter.
Lifestyles of the Fast and Furious
Falcons are roughly crow-sized. Females are about a third larger than males, although they both have bluish to slate grey backs, barred or streaked white to rusty underparts, and a black hood. Adults have black beaks and yellow feet, although their babies may initially have bluish feet. This is natural and not a cause for alarm.
Both males and females are highly territorial. Like eagles, Peregrine falcons are relatively monogamous (polygamy has been documented, but isn't common) and may or may not migrate. Unlike eagles, they are relatively solitary birds.
Traditionally, Peregrine falcons nest on cliffs, laying their eggs directly on a scrape they created in a gravel or sandy substrate. In the midwest, Peregrine falcons generally:
Lay eggs in late March or early April
Hatch in late April to early May, or 33 days after the first egg is laid.
Begin flying in mid-June or later, or about 40 days after hatch.
Peregrines make excellent, attentive parents. The babies cannot thermoregulate (control their temperature) until they are about 10 days old, so Mom spends a great deal of time huddling over them while Dad feeds everyone. As the babies age, both parents spend time hunting. The eyrie is small and the babies, which have among the fastest growth rates in the animal kingdom, are large and hungry. They eat, sleep, poop, and go from white fuzzballs to sleek brown juveniles in about five weeks.
Once they begin flying, the young peregrines spend a lot of learning how to fly and hunt: something that looks a lot like play to most human observers. Their parents will continue to provide some food for their newly fledged young who are not yet self-sufficient. Come fall, the adults may or may not migrate, but their children will disperse. In our experience, the young falcons tend to leave in September. Once they are gone, they are gone. If they do come back to the nest, their parents will defend it from them.
What to expect when falcons are expecting
The new Great Spirit Bluff nest cam wonderfully documented falcon courtship. The falcons engaged in ledge displays on the roof of the nest box, bowing and calling loudly.
As courtship progressed he made a scrape, digging into the gravel with his breast and pushing with his legs to create a depression (males and females will do this - our video shows the male).
Finally, both falcons bowed and e-chupped over the scrape.
The male also courts the female with food. Our video shows him bringing it to the nest box, but falcons also transfer prey midair. There seems to be a little bit of food fight here as well, but think some courtship was going on.
She will probably lay three to four reddish speckled eggs sometime in March. Peregrine falcons do not begin full incubation until after egg number three is laid, so it is normal for her to spend time - even quite a bit of time, depending on how warm it is - away from eggs number one and two. Her eggs should begin hatching 33 days after the third egg is laid.
Mae's eggs, Xcel Energy Allen S. King Plant. Some egg color variation is normal.
During incubation, she will experience hormonal changes that help keep her incubating. She may appear sleepy or lethargic, and will spend a lot of time picking at gravel and sitting more or less quietly on her eggs. She does most of the incubation, although the male will spell her briefly. The male is smaller and may have a harder time covering all of the eggs, depending how many are laid. We can also expect to see egg rolling (Brent, at the Allen S. King plant, is well-known for this) and some shimmying. This is not a particularly active time for the falcons: I've heard Bob refer to incubation as the 'egg doldrums'.
